gpoppitz: I am sorry, but I think that's not enough. Judging from other stand alone added skins like Earth 2 Dark Knight, I would expect you at least would also need the following:
GlobalShaderCache-PC-D3D-SM5.bin
GuidCache.upk
GFxUI.upk
Textures.tfc
Especially the texture file is nasty, because it's 1+ GB big - and looks like they burried the new textures in this general texture file. Very annoying. Maybe someone with knowledge of how to extract and repack stuff from upk-files couls get them separated?
What I did was, put the "playable" and "showcase" and the listed files into a new DLC folder, and give it the following line:
.ShowcaseItems=( Page="Players", Item="BatmanTheBatman", Skin="Playable_Batman_TheBatman", Levels="Showcase_Ambient_Background|Showcase_Players_BatmanTheBatman", Camera="HumanL", SortIndex=191, Unlocked=TRUE )
Same as other DLC do - but this sadly did NOT work.
Then there are some other files changed on STEAM -
OnlineSubsystemSteamworkd.upk
AkAudio.upk
BARKSET_Pred-Red_Hood...
Bank_Small_Px.upk
BmGame.upk
Engine.upk
Pyg.upk
StartupPatch.upk
- some of them heavy hitters which I at the moment don't dare touch, because I don't want to rely on them beeing exchangeable between GOG and STEAM version. Maybe with a bit more time I might compare files sizes STEAM old to GOG. If they match, files might be identical/interchangeable.
On the other hand: what I've seen from the new suit is really disappointing. Textures are low res and seem to be taken directly from SWITCH without any optimization. And it does not even have a shadow! :(
That's so amateurish that I get to the point where I have to say: why bother?
If that's all there is, maybe it would have been better to just leave the game alone...
Thank you for testing. For what its worth, did you also try to edit the main bmgame.ini? That is where the line was originally.